Heat oven at 275°. Warm the olive oil in a skillet over medium heat.
Add the pork steaks and fry 4 to 5 minutes on each side until golden brown, adding the butter when you turn them over.
Remove the pork steaks from the pan and keep them warm in the oven.
Add 4 tablespoons of water to the skillet and deglaze. Bring to a simmer over low heat and slowly stir in the cream and mustard. Add the rosemary and season with salt and pepper.
Remove the pork steaks from the oven and place on plates. Add any juices to the sauce and stir well. Pour sauce over pork steaks and serve immediately.